Design and Development of an IoT-Based Sustainable Seaweed Drying: Temperature uniformity (36-40°C) Validation for “Kappaphycus alvarezii”

Abstract

Introduction: Seaweed farming is a primary livelihood in coastal areas of the Philippines, especially in Tawi-Tawi, where Kappaphycus alvarezii is widely used for carrageenan production. However, traditional sun drying methods, though affordable and straightforward, are inefficient, requiring 5–7 days and exposing seaweed to contamination, inconsistent quality, and income loss for farmers. To address these challenges, the proposed system integrates IoT sensors, renewable energy, and a web-based dashboard to improve drying efficiency and temperature stability. System performance was validated through thermal simulations and real-time testing.

Objectives: The study aims to develop a more efficient and sustainable seaweed-drying system that preserves product quality, shortens drying time, and operates using renewable solar energy. It focuses on designing and validating an IoT-based hybrid dryer that maintains a stable drying temperature, integrates intelligent monitoring with web-based and SMS control, and provides a scalable solution for coastal farming communities. The project supports improved post-harvest processing, enhanced carrageenan quality, and aligns with the UN Sustainable Development Goals.

Methods: The study employed an experimental approach to develop and evaluate an IoT-based hybrid seaweed dryer integrating solar energy, intelligent monitoring, and automated control. An off-grid solar system powered the central controller, sensors, PTC heating element, and exhaust fan, regulating temperature, humidity, and moisture in real time. Drying data were continuously recorded and statistically analyzed to assess drying efficiency, moisture reduction, product quality, and energy consumption relative to traditional methods. A hysteresis-based control algorithm maintained the temperature within 36–40 °C by automatically managing heater and fan operation. Data were logged every 15 minutes to a web-based database for monitoring and analysis.

Results: The IoT-based hybrid dryer prototype successfully integrated an off-grid solar power system, web-based monitoring, and automated control, enabling continuous, sustainable operation. The drying chamber design ensured efficient heat and airflow distribution, validated through simulation and experimental testing. Results showed stable temperature control within the optimal 36–40 °C range, maintaining thermal uniformity within ±2 °C across multiple trials. Real-time IoT monitoring, web-based control, and SMS notifications enabled remote supervision and automated adjustments. The system demonstrated effective humidity reduction, consistent drying performance, and reliability under varying environmental conditions, confirming its suitability for sustainable seaweed post-harvest processing.

Conclusions: This study successfully addressed the limitations of traditional seaweed drying by developing and validating an IoT-based hybrid dryer powered by renewable solar energy. The system achieved stable temperature control within the optimal 36–40 °C range using automated sensor-based monitoring, web-based control, and SMS notifications. Experimental results and simulation testing confirmed uniform heat distribution, effective moisture reduction, and reliable performance under varying environmental conditions. The integration of intelligent control and sustainable energy enhances drying efficiency, product quality, and post-harvest processing, offering a practical and scalable solution for seaweed farmers, particularly in remote coastal communities.